Preparation of improved paint oils



Feb. 23, 1943. R. s. MORSE PREPARATION OF IMPROVED PAINT OILS FiledApril 9, 1940 mmmmmwwmwwmwm Zfl/JT/LL 0T5 BEMOVED RICIIARD S MORSEINVENTOR BY wa/mw N W A TTORNE YS Patented Feb. 23, 1943 PREPARATION OFIMPROVED PAINT OILS Richard S. Morse, Rochester, N. Y., assignor toDistillation Products, Inc., Rochester, N. Y., a

corporation of Delaware Application April 9, 1940, Serial No. 328,701

8 Claims.

This invention relates to a method for preparing improved bodied ordrying oils satisfactory for use in paints and the like.

It is known in the art to prepare thickened oils by subjecting drying orsemi-drying oils and the like to bodying or polymerization treatment.Numerous methods are known in the art but, in general, they compriseheating or oxidation or combinations of the two. Oxidized oils aregenerally made by blowing air through the oil at an elevatedtemperature. Such oils are known as blown oils. This procedure isusually applied to cheaper oils and yields a relatively inferiorproduct. The heating procedure is usually applied to bettergrade oilsand yields a better product. The oil is usually heated in a vacuum or inthe presence of an inert gas such as nitrogen or carbon dioxide.

In Oosterhof Patent 2,065,728 it is proposed that such polymerized orbodied oils be subjected to high vacuum unobstructed path distillationto remove nonpolymers. The procedure involved the removal of relativelylarge amounts of nonpolymers running from -30% and above. The residuewas shown to have improved qualities such as drying time. The removal ofsuch large amounts results in an undistilled residue having highviscosity which tends to form a hard film 0n the vaporizing surfacegiving rise to decomposition and charring during the distillation. Otherdifficulties are encountered.

This invention has for its object to provide a simple and economicalmethod for removing nonpolymerized materials from a bodied oil. Anotherobject is to provide a method for preparing a good quality drying oil bydistillation of bodied oils which will avoid the difliculty of removalof large amounts of non-polymers. A still further object is to provide aprocess which will avoid the above described difiiculties. namely.clogging and charring of the still. Another object is to provide amethod for removing non-polymers which is economical and substantiallysimplified. Other objects will appear hereinafter.

These and other objects are accomplished in accordance with my inventionwhich includes subjecting the bodied or polymerized oil to high vacuumunobstructed path distillation and removing only about 2-12?' ofnon-polymerizable and the like as distillate. I have discovered that theremoval of as little as 2". as distillate yields a drying oil of vastlyimproved qualities and that the removal of more than 12% has nobeneficial effects. In other words, the maximum quality is obtained byremoval of about 10% non-poly- 55 merizable or volatile and the removalof more than 12% is not attended by an increase in desirable properties,such as drying time; filmhardness, water-resistance, etc. For instance,I have found that when my invention is applied to bodied menhaden oilthe removal of as little as 2% as distillate yields an undistilledresidue which has as fast a drying time as linseed oil. This representsaremarkable advance since it is well known that drying oils heretoforeprepared from the fish oils have been far inferior to linseed oil.

My invention is applicable to the distillation of bodied oils preparedby any of the above described bodying treatments or by conventionalbodying treatments known in the art. The process is applicable to bodiedoils which are bodied in any particular degree. It is applicable tofbodied vegetable and marine animal oils, such as bodied linseed, soy,oiticica, walnut, sardine, salmon.v

menhaden, etc. oils. In the case of marine animal oils, it isdesirablethat the bodied oil be prepared from one which has an iodine number ofapproximately or above.

The bodied oil is subjected to distillation under high vacuumunobstructed path distillation conditions. Such distillations are wellknown in the art. The pressure is usually below 2 mm. and is preferablybelow .1 mm., such as .01 to .001 mm. The temperature of distillationwill vary with the particular oil treated and the distillationconditions. Temperatures of -300" C. are generally used. Higher or lowertemperatures are usable but are not commercially satisfactory because ofdecomposition or slow rate of distillation. Temperatures of about -275C. are preferred.

Although it-is perfectly satisfactory to employ an ordinary high vacuumunobstructed path still in which the bodied oil is flowed over thevaporizing surface in a thin film by gravitational force. I much preferto use centrifugal distillation apparatus in which the bodied oil iscaused to flow over the heated vaporizing surface by forces greater thangravity. In one form of apparatus for such distillation the bodied oilis introduced onto the center of a heated rapidly rotating disc. It iscaused to flow thereover in an exceedingly thin film by centrifugalforce. Undistilled residue is removed from the disc at its periphery.The disc is maintained under a high vacuum and volatiles given oil arecondensed upon a condensing surface separated from the disc byunobstructed space. Stills of this type enable the use of temperaturesin the lower portion of the foregoing range. They also enable a highrate of distillation and avoid thermal decomposition.

Such stills are disclosed in detail in Hickman application 99.632 filedSeptember 5, 1936, now Patent No. 2,210,927 dated August 13, 1940.

Regardless of the type of still used, which may be a batch still inwhich the distillant is separated from the condensing surface byunobstructed space, the distillation is adjusted as to time andtemperature so that approximately 242% of distillate is removed. Thedistillate is withdrawn from the still and will be found to consist ofmaterials which are substantially non-polymerizable and which apparentlyinhibit polymerization in the original oil. The 2l2% distillate containsa mixture of complex substances which comprise among other compoundsfree fatty acids, 'sterols, hydrocarbons, decomposition products. andnon-polymerizable glycerides. The undistilled residue is withdrawn fromthe still preferably after cooling and will be found to be a drying oilof high quality.

By the elimination of 2-12% distillate a maximum improvement in dryingtime and hardness is achieved. There appears to be no additionaladvantage to be obtained by the removal of further volatile material.This treatment reduces the drying time to approximately 50% of theoriginal bodied oil and the hardness, water resistance, etc., arelikewise improved.

In the accompanying drawing to which reference is made, I haveillustrated the manner in which the drying properties of bodied oils areimproved by removal of volatile components therefrom. This is shown bythe curve in which percent distillate removed is plotted against dryingtime ofresidue. The notation at 130 represents the drying time oflinseed oil. It is seen that the removal of as little as 2% distillateresults in a residue having a drying time equal to that of linseed oil.Sincethis particular curve was determined by experiments on bodiedmenhaden oil, it Well illustrates the remarkable improvement in dryingqualities obtained by my invention. The results withother oils are muchthe same. The curve also illustrates the fact that in the neighborhoodof 12% there is a critical change and that thereafter no advantage is tobe obtained in drying qualities by removal of additional volatilematter.

Example A heavy bodied menhaden oil having the followingcharacteristics:

Acid value 3.78 Refractive index 1.4840 at 40 C. Viscosity-poises 10.5at C. Iodine value 112.0 Per cent non-saponifiable 3.85 Sap. number222.0

was subjected to high vacuum unobstructed path distillation by causingit to flow in a thin film over a rotating plate of a centrifugal stillhaving a diameter of 14 inches. The plate was maintained at atemperature of 180. The pressure was approximately .001 mm. A 10%fraction was distilled off which was found to be components of lowermolecular weight, mainly free fatty acids and non-saponifiable matter.The undistilled residue was removed, cooled to room temperature, andmixed with a drier such as 5'}? lead in the form of lead naphthenate,.05? manganese in the form of manganese naphthenate, and 05% cobalt inthe form of cobalt naphthenate. The bodied oil-drier mixture was thenspread on glass in a thin film of approximately .001 inch thickness. Thefilm was maintained at room temperature and humidity. A finger smeartest was made every 15 minutes. It was found that the residue had driedto complete hardness in minutes. The drying time of the originalmaterial before distillation was minutes.

In a companion distillation the same 011 was treated to remove 30%distillate. The residue was then tested in the same way. It was foundthat the drying time was substantially the same as that of the residuefrom which only 10% was removed.

What. I claim and desire to be secured by Letters Patent of the UnitedStates is:

1. The process of producing an improved drying oil which comprises incombination subjecting a bodied drying or semi-drying vegetable oranimal oil to high vacuum. unobstructed path distillation until not morethan about 12% of said bodied vegetable or animal oil has been distilledand then removing the undistilled portion of the bodied oil from thestill as the improved drying oil. 7

2. The process of producing an improved drying oil which comprises incombination subjecting a bodied vegetable or animal oil which vegetableor animal oil in its unbodied condition had an iodine number above about120, to high vacuum unobstructed path distillation until not more thanabout 12% of the bodied vegetable or animal oil has been distilled. andthen removing the undistilled portion of the bodied oil from the stillas the improved drying oil.

3. The process of producing an improved drying oil which comprises incombination subjecting a bodied fish oil, which fish oil in its unbodiedcondition had an iodine number above about 120, to high vacuumunobstructed path distillation until approximately 2-12% of the bodiedfish oil has been distilled, and then removing the undistilled portionof the bodied oil from the still as the improved drying oil.

4. The process of producing an improved drying oil which comprises incombination subjecting a bodied fish oil which fish oil in its unbodiedcondition had an iodine number about about 120, to high vacuumunobstructed path distillation until approximately 10% of the bodiedfish oil has been distilled andthen removing the undistilled portion ofthe bodied oil from the still as the improved drying oil.

5. The process of producing an improved drying oil which comprises incombination subjecting a bodied drying or semi-drying vegetable oranimal oil to high vacuum unobstructed path distillation by causing itto flow in a thin film by centrifugal force over a heated vaporizingsurface, applying the distillation treatment until approximately 2-12%of said bodied vegetable or animal oil has been distilled and thenremoving the undistilled portion of the bodied oil from the still as theimproved drying oil.

6. The process of producing an improved drying oil which comprises incombination subjecting a bodied fish oil, which fish oil in its unbodiedcondition had an iodine number above about 120, to high vacuumunobstructed path distillation by causing it to fiow in a thin film bycentrifugal force over a heated rotating vaporizing surface, continuingthe distillation treatment until approximately 2-12% of the bodied fishoil has been distilled and removing the undistilled portion of thcbodied oil from the still as the improved drying oil.

7. The process of producing an improved drying oil which comprises incombination subjecting bodied menhaden oil to high vacuum unobstructedpath distillation until approximately 10% of the bodied menhaden oil hasbeen distilled and then removing the undistilled portion of the bodiedoil from the still as the improved drying oil.

